The disclosure relates to relay systems for providing voice-to-text captioning for hearing impaired users and, more particularly, to a relay system that is compatible with both analog public switched telephone networks and voice over internet protocol (VOIP) telephone service.
Communication systems that support telephone type communications generally take two different forms. A first form referred to as a public switched telephone network (PSTN) uses what's called circuit-switched telephone. This technology works by setting up a dedicated channel (or circuit) between two points for the duration of a call. These telephony systems are based on copper wires carrying analog voice data over dedicated circuits.
The second form which has developed more recently and is referred to as voice over internet protocol (VOIP) is based on digital technologies. VOIP, in contrast to PSTN, uses what is called packet-switched telephone technology. Using this system, voice information travels to its destination in many individual network packets across the Internet. VOIP service is designed to carry voices and dual tone multi-frequency (DTMF) signaling used by a network. However, internet protocol (IP) communication systems do not reliably carry analog data signals (e.g., data signals generated by a modem).
Captioned telephone devices (e.g., a CapTel device) and a captioned telephone system have been developed for providing text transcription of voice communications during a telephone call to hearing impaired assisted users. To this end, a typical captioned telephone device (e.g., an “assisted user's device”) may include a processor, a speaker, a microphone and a display screen and a captioned telephone system may include a relay. When a telephone call occurs between an assisted user using the assisted user's device and another person (hereinafter a “hearing user” using a “hearing user's device”) and captioning is required, a link is made to the relay so that the hearing user's voice signal can be provided to the relay to be transcribed into text and so that the text can be transmitted back to the assisted user's device. The hearing user's voice is broadcast to the assisted user via the speaker and the assisted user's voice is picked up by the microphone and transmitted to the hearing user's device. The transcribed text is presented to the assisted user via the display to view. The transcription and transmission of text is rapid and therefore the text and hearing user's voice signal are presented to the assisted user substantially or close to simultaneously.
There are two general types of assisted user's devices including one line and two line devices. In the case of a one line device, the relay operates between the hearing user's device and the assisted user's device to transcribe the hearing user's voice to text. Thus, a hearing user that dials a phone number associated with an assisted user may be connected first to a relay and the relay may initiate a second connection to the assisted user's device. In this case the hearing user's voice and the assisted user's voice signal travel through the relay to the other user's devices and the text is transmitted form the relay to the assisted user's device directly.
In the case of a two line device, the hearing user's device and the assisted user's device are linked directly to each other for voice communications and the assisted user's device initiates a second link (e.g., the second line in the two line system) to the relay to transmit the hearing user's voice to the relay and receive text back from the relay to present via the display screen.
Captioned phone devices have been extremely successful in the market and have become invaluable tools for hearing impaired users to communicate with other people. One issue with captioned services is that the assisted user's devices and the relay service have costs associated therewith that are over and above the typical costs associated with telephone devices and services used by hearing users. For this reason government agencies have stepped up and often pay for or at least offset some of the additional costs associated with captioning service and the captioning system. For instance, government agencies oftentimes either purchase assisted user devices and distribute those devices to assisted users directly or pay a substantial part of the device purchase price for the assisted users. As another instance, most relay service is funded by a state or the FCC so that, once an assisted user has an assisted user's device, the service is essentially free to the assisted user.
States regulate intrastate telecommunications and all state regulated telecommunications are based on PSTN technology. To provide captioned telephone services, most states have set up telephone equipment distribution programs (EDPs) that purchase assisted user devices and distribute those devices to assisted users that meet qualification requirements set by the state.
The Federal Communications Commission (FCC) regulates interstate services including VOIP based services. Thus, all VOIP telecommunications are regulated by the FCC on a national level. The FCC does not directly purchase assisted user devices and instead allows assisted users to purchase captioned phone devices directly from manufacturers or service providers. The FCC, however, requires that any person wanting to use VOIP captioning service register and certify with the FCC that they require captioning service in order to communicate via a telephone type conversation. The FCC requirements for using captioning services are different than the state requirements.
Because different assisted users have different types of phone service (e.g., PSTN or VOIP), two different types of assisted user devices have been developed, one for use with PSTN service and a second for use with VOIP service.
For many years the US telephone network has been migrating from an analog PSTN system to a VOIP based system for several reasons. First, the internet is generally unregulated and VOIP is less regulated than the PSTN system. Second, VOIP providers have more marketing flexibility and less regulatory overhead than do the traditional wire line companies. Third, VOIP equipment is less expensive to purchase and operate than the traditional PSTN equipment. Moreover, the operating costs are lower for VOIP service than for PSTN services.
When a PSTN based assisted user's device is connected to an IP link, because VOIP does not reliably handle analog data (e.g., modem generated) signals used by the PSTN based device, the PSTN based assisted user's device does not work well. Thus, if an assisted user obtains a PSTN based device and attempts to use that device with a VOIP communication link, captioning results are poor in most cases and the service and device may not be used. Similarly, when an assisted user's telephone service changes from PSTN to VOIP, because IP does not reliably handle analog data signals, a PSTN based assisted user's device becomes unreliable and therefore obsolete. For this reason, while state run EDPs still want to provide captioned telephone devices and services to their residents, the EDPs are reluctant to purchase PSTN based devices that may be rendered obsolete by PSTN to VOIP service migration.
Currently, PSTN based captioned services make use of telephone network signaling to determine the originating and terminating locations for each relay call and, therefore, who has jurisdiction over the call. In one example, a determination may be made as to whether a call is an intrastate, interstate, international, or toll free call. If a determination is made that a call is an intrastate call, a determination may be made as to which state the call originated from and therefore which state has jurisdiction over and regulates the call. With current VOIP technology it is not possible to reliably determine the location of each end point of a call. VOIP based captioned devices cannot reliably provide communication end point information because most IP addresses are dynamically assigned and are not related to a linking communication line.
Nevertheless, the states and the FCC would like to have the same type of summary reports for VOIP based captioned calls that they get for PSTN based captioned calls showing the various call types as described above.
Thus, there is a need for a captioned assisted user's device that can be used with either of PSTN or VOIP communication systems. There is also a need for a captioned assisted user's device and service that will not become obsolete when the underlying technology used to handle communications migrates from PSTN to VOIP. There is also a need for an assisted user's device that can automate the process of determining if a user's device should be set up for VOIP or PSTN service and that can help the assisted user provide required information for using different communication services when needed. There is further a need for a system where information required to establish the location of an assisted user's device is available regardless of the underlying technology used by the device to facilitate communications.